Method of and apparatus for centrifugal concentration



vNov. 16 1926.

F. S. LEWIS METHOD OF AND APPARATUS FOR CENTRTFUGAL CONCENTRATION Original Filed Jan. 31. 192 5 r s W, N5 8 Fran/i agimcer Zewzs Patented Net. re, 1926.

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FRANK S N ER vIumrxs, i or PrriLAnnLrH'm, mm -ma mnriron or AND Qua t CEHTRIFUGAL *ooncnnrniirron".

' Application filed January 31, 1923, 1Seria1 Nd. 615,993. Renewed. April 12; areas.

My'invention relates to separating and concentrating the various metallic or other substances from each other or from, the waste 7 material generally known as the igangue. i V

The method nowemployed, after the material has been ground fine enough to release the values from the-waste, requires it to be screened to different sizes which are there -'after separately concentrated in various ways. The capacity of the variousmean's nowvemployed decreases rapidly as the size of the ground partlcles decreases.

.One object of thepresent'invention is to overcome these defects and disadvantages and to..make a concentrat on of all the sizes at once and, generally. stated, this 1s done,

according to this invention, by subjecting the material bearing fluid to centrifugal and centripetalforces in positiveirelation at one and the same time or, morefaccurately, by subjecting the materialto the resultant of centrifugal force and of'a force acting centr'ipetally. I r V This .resultvmay'be accomplished by the new and novel-method through the agency or a cylinder fitted with. "inlet and outlet pipes at opposite ends and arranged for revolution in a tankcontaining' liquid-and having slots or perforationsprovided through the outer'shell and equipped with cups or lipson the outside i The materialvto be treated mixed withafluid is forced by a pump or other means through the cylinderiwhich is 'madeto revolve in 'theJta'nk offluid at a speed appropriate to drive out through the slots or perforations the (particles :of :relatively heavy; specific gravity by centrifugal force while the water.: and the-gangue are prevented from being forced-out bythe centripetal force ofthe inflow. of. the fluid from the outer tank in which suchcylinder revolves, the cup or lip formation on the outside of the cylinder causing a scooping action which drives the fluid from the tank into the cylinder from which it is carried with the fluid and gangue'therein through the discharge pipe fromthe concentrator, change in the speed of revolution of the the said centrifugal and centripetal pressure to each other or on the resultant'ofthose cylinder having no efiect on the relations of presently described and finally tension'r2 through which thematerial is received an dwith a hollow extension 3 through which the material ifsdischarged aftertreat- I V ment; .These hollow shafts are supported on Tl) tl'le'bearings 4, which'inay be of the ball, 'rollerior other type, and through packing";

glands 5they turn, fwithout'leakage ofmaterial, in respect to the fixed inlet and-outlet connections a and ,6," and theywhole is made 7 to revolvelby pulley 6. 7 isanopen tank to contain fluid surrounding the cylinder 1. 8 1 'are washers'to prevent leakage of fluid from tank '7. VVithin the cylinder 1 there is a second cylinder 'or drum 9 suitably held in po- P1) sition to keep the outside of said cylinder 9 spaced equi-distantfrom the insideof the, outer cylinder 1. Running lengthwise of the outer cylinderare slots lOintowhich are introduced strips ll running lengthwise in the slots and suitably held inposition and projecting beyondthe outer surface of the cylinder 1 and offsuch shape as to cause the I fluid in the tank 7 to be drawn inwardly into ccylinde'r'l; when' the latter is in rotation 1 The stripsll may be niadet'o' project from the surfaceofthecylinder-Ltoa-decreasing extent from thefeed end toward -the discharge end of the cylinder to progressively 1 reduce the pressure of theinwardflow from 1 theijtank to the 'retiolvingcylinder so -;tha;t the heavier concentrates only-will be thrown out of the cylinder 1 as the material first reaches the slots or perforations '10, and the less heavy concentrates due to decreased pressure, Will be discharged along the line of such slots or perforations, so that the various concentrates will fallin various subdivisions at the bottom of the tank from which they can be withdrawn. 1 5

i Obviously modifications may be made in detailsof construction,procedure and op.

eration, without departing from the spirit of the invention, which is not limited as to;

such matters or otherwise than as the prior .0

art and the iappenfiled claims may'require.

lclaingr; r

1. The method of concentration which consists in establishing a flowing stream mixed with the material to be treated and a second body of fluid by interposing between them a perforated rotating cyl'indrical wall having centrip-etally acting impellers, and selectively passing material from the stream through the perforations to the body by subjecting the material to the resultant of centrifugally and centripetally acting forces consequent. upon the rotation the resultant of; centrifugal force and inward flow consequent upon the rotation of the wall and the scooping action of the impellers.

3. Apparatus for concentration which comprises a rotating cylinder internally and externally supplied with fluid and provided at its curved wall with perforations and complemental impellers, whereby'the resultant of the outward centrifugal force due to rotation and the inward force due to the scooping action of the impellers is available for selectively passing material from the interior of the cylinder through'the perforations to' the exterior of the cylinder in opposition to the inward flow of fluid.

&. Apparatus for concentration having in combination a rotary perforated cylinder through which fluid and material are introduced and which is submerged in fluid and providedf withimpellers for establishing inward flow against selectiveicentrifugal expulsion of materlal, substantially as described.

5. Centrifugal concentration apparatus which consists of a cylinder through which the material bearing fluid is forced and which has slots or perforations in its outer surface to bring about a centrifugal pressure in proportion to its rate of revolution, a tank containing fluid in which said cylinder is immersed, said slots or perforations being provided with outward projections to bring about by thevsame revolution of the cylinder a centripetal pressure of inflowing fluid of sufiicient intensity to allow only that portionof the material which is of a greater specific gravity than the gangue to be driven from the cylinder in opposition to such in- .flowing fluid, the centrifugal and centripetal pressures being in positive relation at one and at the same time irrespective of the speed of revolution of the cylinder.

Q 6. Centrifugal concentrating apparatus comprising the. combination of a revolvable cylinder provided with a drum or cylinder of such smaller dimensions that when same is centrally secured within the outer cylinder there will be sufficient space between the cylinders to allow the flow of material bearing fluid-to pass through the machine, means for rotating such cylinder, a tank also containing fluid in which the cylinder is rotated,

said outer cylinder. being equipped with slots-or perforations disposed at a suitable angle to permit the outwardfiow of con-' centrates, said slots or perforations having projecting strips curved or shaped to cause a scooping or centripetal action resulting in an inflowing current of fluid from the tank into the revolving cylinder of sufiicie'nt intensity to prevent the feed fluid and the lighter material or gangue from passing by centrifugal pressure from the revolvingcylinder into the tank.

7. Centrifugal concentrating apparatus as described in claim 6 in which the projecting strips contiguous to the slots or perforations are of decreasing size from the. feed end of the cylinder towards the discharge end of the cylinder in order to reduce the centripetal pressure of the inflow from the tank into the revolving cylinder, and thereby permit the concentrates of lesser specific also to be driven outof cylinder into gravity the tank. i FRANK SPENCER LEl/VIS. 

